Alzheimer's disease (AD) may be associated with mitochondrial
defects. The aim of the present study was to investigate changes in
mitochondrial abundance in peripheral lymphocytes of early and late stage AD
patients. We analysed levels of mitochondrial DNA (mtDNA) and mean fluorescence
intensity (MFI) of the mitochondria-specific antibody 113-1 in CD4+, CD8+, CD19+ and CD56+ peripheral
lymphocytes of early and late stage AD by quantitative real-time PCR and flow
cytometry,respectively. In early stage AD, the levels of mtDNA
were significantly decreased in CD4+, CD19+ and CD56+ peripheral lymphocytes while the MFI of 113-1 staining
was significantly decreased in CD4+ and CD19+ cells. Thus, CD4+ and CD19+ peripheral lymphocytes of early stage AD patients exhibit
mitochondrial depletion, as seen both at the level of DNA and protein.